How does natural selection produce adaptions in a species?

Question

How does natural selection produce adaptions in a species?

Answer 1

What "oldwolves" said is correct, but that doesn't answer the question...

What produces a new adaptation, is a successful mutation, which survives and becomes dominant, and from one perspective, is sexier, which enables it's new feature to be passed on...

DNA is like a copy machine. It makes replicas each time reproduction takes place. However, it is not 100% accurate each time. It often makes mistakes. Perhaps 99.9% of the time, it makes accurate replicas, but 0.1% of the time, it makes an error. Usually this error is discarded, but once in a while it begins a road to something quite new, possibly even a new species...

Examples would be, that the human Blood Type has twice mutated in past 20,000 years from the original "O" Type, into "A" & "B", both of which are now dominant over "O". Though "O" still comprises 46% of world's Blood Type, "A" now makes up 39%, "B" 11%, and "AB" 4%...

So 20,000 years later, the original human Blood Type is a minority...Natural selection consists of change in lifestyle, climate and/or diet. When Hunter/Gatherer "O"s began farming, living in cities & domesticating animals, this is when these two successful mutations began to thrive & multiply...

One could say, it is the drastic change, which leads to the increased chance of error, at the level of DNA replication!

Answer 2

Positive selection of a gene boils down to reproductive success.  An example of this would be Homo sapien skin color in the higher lattitudes (climates with less sunlight).  Darker skinned women tended to get rickets due to less sunlight getting through the skin to produce the needed vitamin D.  Therefore they were far more likely to die during childbirth.  The reverse is true in lower lattitudes as too much sunlight destroyed folic acid & resulted in increased infant mortality.  Therefore we have dark skinned & light skinned people.

Animals tend to develop colors that enhance their ability to hide or elude predators. Animals that can run faster or catch prey more easily will have a better chance of producing more viable offspring.

Answer 3

Trial and error. Two headed dear keeps running into trees.Quickly gets caught by wolves . Dinner. Unable t o reproduce.One head Clears the tree. Lives to reproduce. Species continues.